JUPYTER_CONFIG_PATH does not work.

[rickwierenga]

Describe the bug

JUPYTER_CONFIG_PATH does not work.

To Reproduce

mkdir custom
touch custom/custom.js
echo "console.log('test')" > custom/custom.js 
JUPYTER_CONFIG_PATH=$(pwd) jupyter notebook

Expected behavior

The file should be loaded; test should be printed in the console.

Desktop (please complete the following information):

• OS: macOS 12.3.1
• Browser Safari 15.4, Chromium 105.0.5175.0 (Developer Build)